<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_View
 * @subpackage Helper
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @version    $Id: Abstract.php 18951 2009-11-12 16:26:19Z alexander $
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */

/**
 * Abstract class representing container for placeholder values
 *
 * @package    Zend_View
 * @subpackage Helper
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
abstract class Zend_View_Helper_Placeholder_Container_Abstract extends ArrayObject
{
	/**
	 * Whether or not to override all contents of placeholder
	 * @const string
	 */
	const SET    = 'SET';

	/**
	 * Whether or not to append contents to placeholder
	 * @const string
	 */
	const APPEND = 'APPEND';

	/**
	 * Whether or not to prepend contents to placeholder
	 * @const string
	 */
	const PREPEND = 'PREPEND';

	/**
	 * What text to prefix the placeholder with when rendering
	 * @var string
	 */
	protected $_prefix    = '';

	/**
	 * What text to append the placeholder with when rendering
	 * @var string
	 */
	protected $_postfix   = '';

	/**
	 * What string to use between individual items in the placeholder when rendering
	 * @var string
	 */
	protected $_separator = '';

	/**
	 * What string to use as the indentation of output, this will typically be spaces. Eg: '    '
	 * @var string
	 */
	protected $_indent = '';

	/**
	 * Whether or not we're already capturing for this given container
	 * @var bool
	 */
	protected $_captureLock = false;

	/**
	 * What type of capture (overwrite (set), append, prepend) to use
	 * @var string
	 */
	protected $_captureType;

	/**
	 * Key to which to capture content
	 * @var string
	 */
	protected $_captureKey;

	/**
	 * Constructor - This is needed so that we can attach a class member as the ArrayObject container
	 *
	 * @return void
	 */
	public function __construct()
	{
		parent::__construct(array(), parent::ARRAY_AS_PROPS);
	}

	/**
	 * Set a single value
	 *
	 * @param  mixed $value
	 * @return void
	 */
	public function set($value)
	{
		$this->exchangeArray(array($value));
	}

	/**
	 * Prepend a value to the top of the container
	 *
	 * @param  mixed $value
	 * @return void
	 */
	public function prepend($value)
	{
		$values = $this->getArrayCopy();
		array_unshift($values, $value);
		$this->exchangeArray($values);
	}

	/**
	 * Retrieve container value
	 *
	 * If single element registered, returns that element; otherwise,
	 * serializes to array.
	 *
	 * @return mixed
	 */
	public function getValue()
	{
		if (1 == count($this)) {
			$keys = $this->getKeys();
			$key  = array_shift($keys);
			return $this[$key];
		}

		return $this->getArrayCopy();
	}

	/**
	 * Set prefix for __toString() serialization
	 *
	 * @param  string $prefix
	 * @return Zend_View_Helper_Placeholder_Container
	 */
	public function setPrefix($prefix)
	{
		$this->_prefix = (string) $prefix;
		return $this;
	}

	/**
	 * Retrieve prefix
	 *
	 * @return string
	 */
	public function getPrefix()
	{
		return $this->_prefix;
	}

	/**
	 * Set postfix for __toString() serialization
	 *
	 * @param  string $postfix
	 * @return Zend_View_Helper_Placeholder_Container
	 */
	public function setPostfix($postfix)
	{
		$this->_postfix = (string) $postfix;
		return $this;
	}

	/**
	 * Retrieve postfix
	 *
	 * @return string
	 */
	public function getPostfix()
	{
		return $this->_postfix;
	}

	/**
	 * Set separator for __toString() serialization
	 *
	 * Used to implode elements in container
	 *
	 * @param  string $separator
	 * @return Zend_View_Helper_Placeholder_Container
	 */
	public function setSeparator($separator)
	{
		$this->_separator = (string) $separator;
		return $this;
	}

	/**
	 * Retrieve separator
	 *
	 * @return string
	 */
	public function getSeparator()
	{
		return $this->_separator;
	}

	/**
	 * Set the indentation string for __toString() serialization,
	 * optionally, if a number is passed, it will be the number of spaces
	 *
	 * @param  string|int $indent
	 * @return Zend_View_Helper_Placeholder_Container_Abstract
	 */
	public function setIndent($indent)
	{
		$this->_indent = $this->getWhitespace($indent);
		return $this;
	}

	/**
	 * Retrieve indentation
	 *
	 * @return string
	 */
	public function getIndent()
	{
		return $this->_indent;
	}

	/**
	 * Retrieve whitespace representation of $indent
	 *
	 * @param  int|string $indent
	 * @return string
	 */
	public function getWhitespace($indent)
	{
		if (is_int($indent)) {
			$indent = str_repeat(' ', $indent);
		}

		return (string) $indent;
	}

	/**
	 * Start capturing content to push into placeholder
	 *
	 * @param  int $type How to capture content into placeholder; append, prepend, or set
	 * @return void
	 * @throws Zend_View_Helper_Placeholder_Exception if nested captures detected
	 */
	public function captureStart($type = Zend_View_Helper_Placeholder_Container_Abstract::APPEND, $key = null)
	{
		if ($this->_captureLock) {
			require_once 'Zend/View/Helper/Placeholder/Container/Exception.php';
			throw new Zend_View_Helper_Placeholder_Container_Exception('Cannot nest placeholder captures for the same placeholder');
		}

		$this->_captureLock = true;
		$this->_captureType = $type;
		if ((null !== $key) && is_scalar($key)) {
			$this->_captureKey = (string) $key;
		}
		ob_start();
	}

	/**
	 * End content capture
	 *
	 * @return void
	 */
	public function captureEnd()
	{
		$data               = ob_get_clean();
		$key                = null;
		$this->_captureLock = false;
		if (null !== $this->_captureKey) {
			$key = $this->_captureKey;
		}
		switch ($this->_captureType) {
			case self::SET:
				if (null !== $key) {
					$this[$key] = $data;
				} else {
					$this->exchangeArray(array($data));
				}
				break;
			case self::PREPEND:
				if (null !== $key) {
					$array  = array($key => $data);
					$values = $this->getArrayCopy();
					$final  = $array + $values;
					$this->exchangeArray($final);
				} else {
					$this->prepend($data);
				}
				break;
			case self::APPEND:
			default:
				if (null !== $key) {
					if (empty($this[$key])) {
						$this[$key] = $data;
					} else {
						$this[$key] .= $data;
					}
				} else {
					$this[$this->nextIndex()] = $data;
				}
				break;
		}
	}

	/**
	 * Get keys
	 *
	 * @return array
	 */
	public function getKeys()
	{
		$array = $this->getArrayCopy();
		return array_keys($array);
	}

	/**
	 * Next Index
	 *
	 * as defined by the PHP manual
	 * @return int
	 */
	public function nextIndex()
	{
		$keys = $this->getKeys();
		if (0 == count($keys)) {
			return 0;
		}

		return $nextIndex = max($keys) + 1;
	}

	/**
	 * Render the placeholder
	 *
	 * @return string
	 */
	public function toString($indent = null)
	{
		$indent = ($indent !== null)
		? $this->getWhitespace($indent)
		: $this->getIndent();

		$items  = $this->getArrayCopy();
		$return = $indent
		. $this->getPrefix()
		. implode($this->getSeparator(), $items)
		. $this->getPostfix();
		$return = preg_replace("/(\r\n?|\n)/", '$1' . $indent, $return);
		return $return;
	}

	/**
	 * Serialize object to string
	 *
	 * @return string
	 */
	public function __toString()
	{
		return $this->toString();
	}
}
